Optical microscopy is used to magnify objects, such as cells and tissue structures. There are several types of microscopy; LIDI has bright field, phase contrast, and fluorescence. Bright field microscopy is used to assess tissue pathology in stained (e.g., Hematoxylin and Eosin) sections as well as parasitemia in Giemsa-stained thin blood films. For bright field microscopy, LIDI has an EVOS XL Core microscope (20x, 40x, and 100x lenses) and a dissecting microscope both with color CCD camera and imaging software. Phase contrast microscopy is used to evaluate cell morphology in tissue culture; for this, LIDI uses a Zeiss Primostar inverted microscope. Fluorescence microscopy is used to analyze cells or tissue sections for protein or RNA levels and/or localization. LIDI has an EVOS FL microscope with 20x, 40x, and 100x lenses, digital camera, fluorescence cubes for DAPI, FITC, APC, and TxR, and imaging software. For confocal microscopy, TSRI has a Zeiss LSM 780 laser scanning confocal unit attached to a Zeiss Observer Z1 microscope with infinity corrected optics (10x, 20x, 40x, 63x, and 100x). The LSM 780 has 7 lasers (405, 458, 488, 514, 561, 594, and 633nm). This microscope is hardware and software capable for: fluorescence energy transfer measurements, fluorescence recovery after photobleaching and fluorescence correlation. Two photon microscopy is available at USCD National Center for Microscopy and Imaging Research (NCMIR) with three custom built 2 photon microscopes.